Draft controlling and back draft



June 9 v P. A. VIOLA ET AL 2,557,210

DRAFT CONTROLLING AND BACKDRAFT DIVERSION DAMPER DEVICE FOR FURNACESFiled May 4, 1948 3nventors 4. 724, (IttorneBS Patented June 19, 1951'UNITED DRAFT CONTROLLING AND BACK DRAFT DIVERSION DAMPER DEVICE FOR FUR-NAG-ES Paul A. Viola and Joseph A. Viola, Bridgeport, Conn.

Application May 4', 1948, Serial N 0.. 24,954

Claims.

This invention relates to a draft control for furnaces. It could be usedwith practically any type of furnace, but is designed primarily for oilor gas: furnaces, and has for an object to provide a simple andeffective device for preventing the downdraft from the chimney passingback into the furnace to possibly blow out the flame or force the gasesor products of combustion out into the room.

Another object is to prevent the circulation of cooling air through thefurnace to absorb heat and carry it up the chimney when the burner isnot operating.

With the foregoing and other objects in view, we have devised theconstruction illustrated in the accompanying drawing forming a part ofthis specification. It is, however, to be understood the invention isnot limited to the specific details of. construction and arrangementshown, but may embody various changes and modifications within the scopeof the invention.

In this drawing:

Fig. 1 is a partial side elevation and partial section showing use ofthe device in. a furnace;

Fig. 2 is a longitudinal vertical section through the device taken onsubstantially the line 2-2. of Fig. 4;

Fig. 3 is a horizontal longitudinal section taken substantially on line33 of Fig. 4, and

Fig. 4 is an end view looking from the left of Fig. 2.

A furnace of any desired type is indicated at 5, with the usual smokepipe 6 and any type of oil burner indicated diagrammatically at 1. Itis, however, to be understood this is shown merely by way of example, asthe device may be used with other types of burners, such, for example,as gas or coal burners. In the pipe is the usual thermostat 8 operatinglimit switch 9 to turn off the burner when the heat reaches a certainamount, and mounted in this pipe, preferably in the last section as itenters the chimney l 0, is our device indicated as a whole at H.

The device comprises a section of stove pipe l2 adapted to be insertedat the outlet end in the opening to the flue of the smoke-stack orchimney, and at its other end telescoping with the next standardstovepipe section 6. Within this section I2 is a tapered section I3which may be made of the sheet metal used for making standard stovepipeand the section [2, and this tapered section is of a size so that itslarger end l4 fits and is secured in the section l2 adjacent the endnearest the furnace, with its outlet or smaller end I5 adjacent thedischarge end of the section I2.

2 This outlet is controlled by a light hinged damper i5. pivotallymounted. on the top of the tapered section by any suitable. means, such,for example, as asubstantially U-shaped bracket I! which may be securedby any suitable means. on the top of the tapered section.

The damper is mounted on a pivot rod l8 extending at one end through theside of the section l2, where it is bent laterally to form a rearwardlyextending arm I8a on which is adjustably mounted a counterweight 49which is adjustable along the rod and may be secured in any adjustedposition by the set screw [9a. The rod is formed with an intermediatebend 20 to limit forward movement of weight i9 so that should the weight[9 become loosened or should a child or someone adjust it on the rod, itcould not move nearer than this bend to the pivot, so that the dampercould not overbalance this weight sufficiently that the damper would notopen by draft from the furnace. There may be a small Weight Zl mountedin the damper if it is found the damper itself is not of sufficientweight for the counter-balancing effect, and although the damper may beof other shapes it is preferably substantially conical as shown.

The weight I 9 is so adjusted that with no fire in the furnace thedamper l6 will just close, so that a very light draft will open thedamper, as indicated by the dotted line in Fig. 2, as soon as the burneris lighted or becomes operative, but any down or backdraft will closethis damper so that. it will not blow or flow back into the furnace toblow out the flame of the burner or to force the products of combustionor other gases out into the room. To further assist this action, theouter section i2 is provided with openings 22 on opposite sides and justforwardly of the larger or entrance end of tapered section I3, so thatthe downdraft flowing toward the furnace, after closing the damper I6,will pass out through these openings 22. These openings also permit airto pass into the pipe during normal operation to help control the draftand to keep it more uniform.

A still further important operation and effect of this device is thatwhen the burner is not operating, as for example, when the temperaturehas reached a certain limit, as effected by the usual automaticthermostat controls, this damper closes and prevents the fiow of coldair through the furnace and up the chimney, which flow of cold airwould, of course, have a cooling eifect on the furnace and carry aconsiderable amount of heat up the chimney. It therefore effects agreater efficiency in operation of the furnace and a material saving infuel by preventing this loss up the chimney. This, in addition to thesafety features as described and better control of the draft, has madethis device very eifective in actual use. Due to its simplicity it canbe manufactured at relatively low cost and is easily installed in thesmoke pipe.

Having thus set forth the nature of our invention, we claim:

1. A draft control for furnaces comprising a section of stove pipeadapted to form a, portion of the smoke pipe from the furnace to thechimney, a tapered section in the first section arranged with its largerend fitting the inside of the first section in substantially gas tightrelationship therewith and its smaller end spaced substantially inwardlyof the inner surface of the first section, said tapered section beinghollow and open at both ends to provide a gas passageway entirelytherethrough, a pivoted damper at the smaller end of the taperedsection, means balancing the damper to swing outwardly away from thisend under the influence of a draft from the furnace and to be swung by aback draft to close the opening upon the occurrence of a reverse draft,and the first section being provided with air inlet means leading to thespace between this section and the tapered section.

2. A draft control for furnaces comprising a section of stove pipeadapted to form a portion of a substantially horizontal smoke pipeleading from the furnace to the chimney, a tapered section in the firstsection open at both ends to provide a gas passageway entireltherethrough and arranged with its larger end forming the inlet end andthe smaller end the outlet, the larger end fitting the inside of thefirst section in substantially gas tight relation therewith and thesmaller end spaced substantially inwardly of the inner surface of thefirst section, a pivoted damper over the smaller outlet end, a lateralarm connected to the damper, a balance weight adjustably mounted on saidarm, said damper being arranged to swing outwardly from said smaller endunder influence of a draft from the furnace and to be swung back toclose the opening by a back draft from the chimney, and the firstsection being provided with air inlet openings leading to the spacebetween this section and the tapered section.

3. A draft control for furnaces comprising a section of stove pipeadapted to form a portion of a substantially horizontal smoke pipeleading from the furnace to the chimney, a, tapered section in the firstsection open at both ends to provide a gas passageway entirelytherethrough and arranged with its larger end fitting the outer sectionin substantially gas tight relationship therewith and its smaller endforming the outlet spaced substantially inwardly of the inner surface ofthe first section, a damper over the outlet end, means pivotallymounting said damper on the tapered section to swing outwardly away fromsaid smaller end under the influence of a draft from the furnace nd tobe swung by a back draft to close the opening in said smaller end uponthe occurrence of a reverse draft, said mounting means comprising apivot rod including a laterally extending arm, a balance weightadjustably mounted on the rod, said rod being provided with a stop meansfor said weight between the weight and pivot portion of the rod to limitmovement of the weight toward this portion, and the outer section beingprovided with air inlet openings leading to the space between thissection and theinner tapered section.

4. A draft control for furnaces comprising a, section of stove pipeadapted to form a portion of the smoke pipe from the furnace to thechimney, a tapered section in the first section open at both ends toprovide a gas passagewa entirely therethrough and arranged with itslarger end fitting in the outer section in substantially gas tightrelationship therewith, and its smaller end spaced substantiallyinwardly of the inner surface of this first section, a pivoted damperclosing the smaller end, means balancing the damper so that it will moveoutwardly away from said end to open position under the influence of adraft from the furnace and will be swung back to close the opening uponthe occurrence of a reverse draft from the chimney, and the outer firstsection being provided with air inlet openings adjacent the larger endof the tapered section leading to the space between the outer andtapered sections.

5. A draft control for furnaces comprising a section of stove pipeadapted to form a portion of the smoke pipe from the furnace to thechimney, :a tapered section in the first section open at both ends toprovide a gas passageway entirely therethrough and arranged with itslarger end forming the inlet end and the smaller end the outlet, thelarger end fitting the inside of the first section in subtsantially gastight relationship therewith and the smaller end spaced substantiallyinwardly of the inner surface of the first section, a pivoted damperover the smaller outlet end, a lateral arm connected to the damper, abalance weight adjustably mounted on said arm, said damper beingarranged to swing outwardly away from said smaller end under theinfluence of a draft from the furnace and be swung by a back draft toclose against said end upon the occurrence of a reverse draft from thechimney, and the outer section being provided with air inlet openingsadjacent the larger end of the inner section leading to the spacebetween the outer and inner sections.

PAUL A. VIOLA. JOSEPH A. VIOLA.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 80,832 Pastorius Aug. 11, 18681,196,117 Kiefer Aug. 29, 1916 1,856,478 Greenberg May 3, 1932

